1. Technical Field
The present invention relates to an apparatus for manufacturing fluorescent layers and, more particularly, to an apparatus for manufacturing fluorescent layers, which converts light from a light-emitting diode into white light by varying a wavelength of the light emitted from the light-emitting diode.
2. Description of the Related Art
Recently, a light-emitting diode in which Al or In has been added to GaN has been in the spotlight owning to longer lifespan, low power consumption, excellent brightness, and eco-friendly factors not harmful to the human being, as compared with a conventional incandescent electric lamp. In particular, a light-emitting diode chip that provides white light by adopting a fluorescent layer has been in the spotlight.
The light-emitting diode is being used in vehicle lamps, traffic lights, and the Back Light Unit (BLU) of a liquid crystal display device because of the above advantages.
Recently, MacAdam's Ellipse Rule was proposed as an index for estimating whether or not color coordinates measured in an artificial light source are the same as color coordinates seen by an eye of the human being. This MacAdam Ellipse Rule provides a 4-step criterion. Currently, in the United States, an artificial light source is not allowed to be sold if the artificial light source does not comply with three steps of the MacAdam Ellipse Rule. In order to satisfy the three steps of the MacAdam's Ellipse Rule, it is very important to reduce a color deviation in white light.
Meanwhile, Korean Patent Laid-Open Publication No. 10-2008-0070193 discloses a fluorescent film in which fluorescent materials are formed on a surface of a film made of resin. If the fluorescent film is attached to a light-emitting diode, the fluorescent film is not effectively attached to a desired position of the light-emitting diode due to electrostatic force or adhesive force occurring between the fluorescent materials and the film made of resin. Accordingly, it is difficult to reduce a color deviation in white light, and a reliability problem is generated due to poor adhesive force between the light-emitting diode and the fluorescent film.
Furthermore, the above fluorescent film includes the fluorescent materials formed on a surface of the film made of resin. In order to attach the fluorescent film to a light-emitting diode in which electrode pads are formed, the fluorescent film needs to be previously cut in a form in which the fluorescent film can be disposed in parts other than the electrode pads. As a result, there is a problem in that an additional process is added.